This invention concerns castors for use on furniture and in particular on office chairs.
In various countries, standards have been laid down regulating certain features of the construction of castors which are available on the market. For example, in some countries, the regulations require that a chair castor be braked only when a load is applied to the castor as a result of a person sitting on the chair to which the castor is attached. In other countries, by contrast, the regulations require that the castor normally be braked and the braking effect removed when a load is applied to the castor as a result of a person sitting in the chair.
Consequently, the design requirements for different countries are not the same, and hitherto it has been necessary to design different castors to suit the different requirements. This is inconvenient and costly.